Anelosimus nelsoni Agnarsson

Agnarsson, Ingi & Zhang, Jun-Xia, 2006, New species of Anelosimus (Araneae: Theridiidae) from Africa and Southeast Asia, with notes on sociality and color polymorphism, Zootaxa 1147, pp. 1-34 : 26-28

Anelosimus nelsoni Agnarsson n. sp.

( Figs 14 A–C, 15 A–F, 16 A–G, 17 A–F)

Types

Male holotype and paratype (1 Ψ) from South Africa, Kwazulu Natal St. Lucia Estuary, Fanies Island, 5 km S of Cape Vidal, 28 °06’ 41 ”S, 32 ° 25 ’ 51 ”E 5.iv. 2001,I. Agnarsson et al., deposited in NMNH

Diagnosis

Anelosimus nelsoni n. sp. males can be separated from other Anelosimus by the shape of the large and bifurcate ‘embolic division b’, and the conspicuous hook on the distal portion of the embolus base ( Figs 14 A, 15 B–D). Females differ from all other Anelosimus by the copulatory duct wrapping the spermathecae ( Fig. 14 C).

Description

Male (holotype): Total length 2.08. Prosoma 1.20 long, 0.90 wide, pale yellowish, center and a narrow rim dark. Sternum 0.75 long, 0.60 wide,, pale yellowish, lightest in center. Opisthosoma 1.10 long, 0.90 wide, 0.90 high. Pattern other Anelosimus . Eyes subequal in size about 0.07 in diameter. Clypeus height about 2.3 times AME diameter. Leg I femur 1.60, patella 0.50, tibia 1.55, metatarsus 1.40, tarsus 0.62. Femur about 6 times longer than wide. Leg formula 1423. Leg pale yellowish, narrow dark rings near all joints (except coxae–trochanter). 4–7 small trichobothria dorsally on all tibia, 5–6 on tibia I, 6 on tibia III. 2 prolateral and 1 retrolateral trichobothrium on palpal tibia. Stridulatory pick row on opisthosoma distinctly curved, with distal setae compressed, consisting of approximately 27–32 modified setal bases ( Figs 16 E–F). Epiandrous gland spigots in two distinctly separate groups with approximately 6–7 fusules ( Fig. 16 C).

Palpal organ as in Figures 14 A, 15 A–F.

Female (paratype): Total length 2.60. Prosoma 1.40 long, 1.00 wide, pale yellowish, center and a narrow rim dark. Sternum 0.90 long, 0.65 wide, pale yellowish, lightest in center. Opisthosoma 1.45 long, 1.25 wide. Pattern as in other Anelosimus . Eyes subequal in size about 0.07 in diameter. Clypeus height about 2.5 times AME diameter. Leg I femur 1.60, patella 0.50, tibia 1.35, metatarsus 1.25, tarsus 0.60. Femur about 6 times longer than wide. Leg formula 1423. Leg pale yellowish, narrow dark rings near all joints (except coxae­trochanter). 5–6 small trichobothria dorsally on all tibia, 5–6 on tibia I, 5 on tibia III. 4 dorsal trichobothria on palpal tibia on one side ( Fig. 17 E), 3 on the other. Epigynum as in Figures 14 B–C, 16 A–B.

Distribution

Only known from the type locality.

Natural history

This species was collected beating bushes and trees during day. Webs were not seen. The habitat was a small, open, forest patch, situated on a small river island.

Phylogenetics

Anelosimus nelsoni n. sp. was included in the phylogenetic analyses of Agnarsson (2005, 2006) as Anelosimus sp. 5 South Africa. In these analyses A. nelsoni n. sp. was sister to the ‘epigynal scape clade’ (see Agnarsson 2006), together these form a clade here termed the ‘basal cymbial hood clade’ ( Fig. 1), referring to a synapomorphy shared by all species in it ( Fig. 15 F).

m.